BIOL 530
We will use the latitudinal increase in diversity towards the equator as a launching point to explore how diversity forms, is maintained, and disappears, and why we find such dramatic variation in diversity around the world.
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Course discussions will focus on both evolutionary and ecological perspectives of diversity, and we will review various hypotheses to explain latitudinal diversity gradients.
Class schedule
Mondays 08:30 - 10:00am & Thursdays 10:00 - 11:30am
Week 1 Thursday, Sept 4, 2025 Introduction & complex questions in science
Week 2 Monday, Sept 8, 2025 Strong inference
Thursday, Sept 11, 2025 Multiple working hypotheses
Week 3 Monday, Sept 15, 2025 Biological patterns across latitude
Thursday, Sept 18, 2025 A framework for studying diversity gradients
Week 4 Monday, Sept 22, 2025 The latitudinal gradient through deep time
Thursday, Sept 25, 2025 Latitudinal Variation in Cladogenesis
**Student presentations begin**
Week 5 Monday, Sept 29, 2025 Latitudinal Variation in Extinction - Teddy (presenter), Gabby (co-presenter)
Thursday, Oct 1, 2025 Janzen's Hypothesis - Harani (presenter), Brooke (co-presenter)
Week 6 Monday, Oct 6, 2025 Asynchrony of Seasons Hypothesis - Taylor (presenter), Ausha (co-presenter)
Thursday, Oct 9, 2025 Shifting Ranges Hypothesis - Serena (presenter), Kira (co-presenter)
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Week 7 Reading week (October 13-17)
Week 8 Monday, Oct 20, 2025 Species Energy - Rates of Evolution Hypothesis - Trinity, (presenter), Mya (co-presenter)
Thursday, Oct 23, 2025 Biotic vs Abiotic Selection Hypothesis - Romta (presenter), Teddy (co-presenter)
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Week 9 Monday, Oct 27, 2025 Geographic Area Hypothesis - Brooke (presenter), Taylor (co-presenter)
Thursday, Oct 30, 2025 Species Energy - Number of Individuals Hypothesis - Eva (presenter), Amelie (co-presenter)
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Week 10 Monday, Nov 3, 2025 Glacial Extinctions Hypothesis - Nicole (presenter), Romta (co-presenter)
Thursday, Nov 6, 2025 Tropical Niche Conservatism Hypothesis - Mya (presenter), Serena (co-presenter)
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Week 11 Monday, Nov 10, 2025 Density-dependent Mortality Hypothesis - Ausha (presenter), Eva (co-presenter)
Thursday, Nov 13, 2025 Climate Stability - Population Size Hypothesis - Kira (presenter), Harani (co-presenter)
Week 12 Monday, Nov 17, 2025 Biotic Interactions - Ecological Breadth Hypothesis - Amelie (presenter), Nicole (co-presenter)
Thursday, Nov 20, 2025 Evolutionary Time Hypothesis - Gabby (presenter), Trinity (co-presenter)
Week 13 Monday, Nov 24, 2025 Environmental Harshness Hypothesis - Vennila (presenter), Zainab (co-presenter)
Thursday, Nov 27, 2025 Geometric Constraints Hypothesis - Zainab (presenter), Vennila (co-presenter) ​
Week 14 Monday, Dec 1, 2025 Wrap-up discussion
Grade breakdown
Presentation of hypothesis & predictions 30% instructions & rubric
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Co-presentation of critical assessment 15% instructions & rubric
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Major written paper 35% instructions & rubric
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In-class participation 20% instructions & rubric
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There are no formal exams in this class.
Class readings (I will send out readings each week by email)
Week 1 Thursday, Sept 4, 2025 no readings
Week 2 Monday, Sept 8, 2025 Platt 1964 Science 146:347-353
Thursday, Sept 11, 2025 Chamberlin 1965 Science 148:754-759
Week 3 Monday, Sept 15, 2025 Hillebrand 2004 American Naturalist 163: 192-211
Thursday, Sept 18, 2025 Jablonski et al. 2006 Science 314: 102-106
Week 4 Monday, Sept 22, 2025 Mannion et al. 2014. TREE 29: 42-50
Thursday, Sept 25, 2025 Weir & Schluter 2007 Science 315: 1574-1576
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**Student presentations begin**
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Week 5 Monday, Sept 29, 2025 Martin et al. 2007 J. Evol. Biol. 20: 930-93
Thursday, Oct 1, 2025 Ghalambor et al. 2006 Integr. & Comp. Biol. 46: 5-17
Week 6 Monday, Oct 6, 2025 Martin et al. 2009 Ideas Ecol. Evol. 2: 9-17
Thursday, Oct 9, 2025 Dynesius & Jansson 2000 PNAS 97: 9115-9120
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Week 7 Reading week (October 13-17)
Week 8 Monday, Oct 20, 2025 Allen et al. 2006 PNAS 103: 9130-9135
Thursday, Oct 23, 2025 Schemske 2009 book chapter
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Week 9 Monday, Oct 27, 2025 Rosenzweig 1992 J. Mammalogy 73: 715-730
Thursday, Oct 30, 2025 Wright 1983 Oikos 41: 496-506 &
Currie & Paquin 1987 Nature 329: 326-327
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Week 10 Monday, Nov 3, 2025 Adams & Woodward 1989 Nature 339: 699–701 &
McGlone 1996 Global Ecol. Biogeogr. Letters 5: 309-314
Thursday, Nov 6, 2025 Wiens & Donaghue 2004 TREE 19: 639-644
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Week 11 Monday, Nov 10, 2025 Hille Ris Lambers et al. 2002 Nature 417: 732-735
Thursday, Nov 13, 2025 Connell & Orias 1964 Am. Naturalist 98: 399-414
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Week 12 Monday, Nov 17, 2025 Dyer et al. 2007 Nature 448: 696-699
Thursday, Nov 20, 2025 Fischer 1960 Evolution 14: 64-81 (excerpt only)
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Week 13 Monday, Nov 24, 2025 Brown & Gibson 1983 (excerpt from book) &
Thiery 1982 Biological Reviews 57: 671-710 (excerpt)
Thursday, Nov 27, 2025 Colwell & Lees 2000 Trends in Ecology & Evolution 15:70-76
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Week 14 Monday, Dec 1, 2025 Jetz & Fine 2012 PLoS Biology 10: e1001292
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